VEWS® Technology Platform

Our VEWS® technology platform is a miniature multi-channel NIR discrete spectroscopy system with unique features:

  • Up to four wavelengths with precise, fully protected constant current control LED drivers. This permits multiple sites to be monitored simultaneously
  • Ambient light interference compensated using time division multiplex system at over 1,000 times per second. This allows the VEWS® device to ignore normal internal light sources such as fluorescent lights
  • Powerful 32-bit internal processor with over 40 megabytes of memory. This enables sophisticated signal processing and analysis to be performed digitally for increased stability
  • 4.3" colour touch-screen with clear, concise user interface with integrated protocol directions and ease-of-use

VEWS® exploits the physiological principle of auto-regulation, particularly local blood flow regulation. Autoregulation is the ability of an organ to strive to maintain constant blood flow despite changes in perfusion pressure. If arterial disease is not present, local autoregulation will maintain the flow despite the reduced blood pressure, which is detectable as an increase in pulsatile blood volume caused by arterial relaxation. If arterial disease is present, local compensating mechanisms such as the arterial contractile myogenic (muscular) response and arterial dilatory shear stress response are activated even in the resting position; thus the added challenge of maintaining homeostasis during the leg raise results in a blunted response.

Employing a functional test with discrete spectroscopy quantifiably assess changes in skin colour and arterial blood volume between two positions, one at supine and the second with a leg raised. This allows the severity of arterial disease to be measured using the resting position as a reference, thus generating an index of before/after responses. The resting position therefore compensates for static components such as skin colour and thickness, or arterial oxygen saturation between the two positions.


For rapid, non-invasive assessment of Peripheral Arterial Disease, to prevent heart disease and stroke